Rochester refund

I paid a deposit in a laybye on 03 October to Rochester the Grove. I changed my mind a week later and asked then for a refund. They asked me to send them my banking details. 3 weeks later they send mer a message that my banking details is not clear. So I sent them a bank confirmation letter. Again I received a message that the account number was not clear. I download my bank confirmation and emailed it them on 15 Dec. To date they have still not refunded me my money. Their service is pathetic and there had been no correspondence from them at all.